<!DOCTYPE html>
<html>
<head lang="en">
  <meta charset="UTF-8">
  <title></title>
</head>
<body>

<input type="text">
<div>
  你输入的内容是：<span></span>
</div>
<script type="text/javascript" src="../../js/jquery/jquery-1.11.1.js"></script>
<script type="text/javascript">
   $(function () {  // 等同于document.ready   不等于window.onload
     $('input').keyup(function () {
       $('span').html($(this).val())
     })
   })
</script>
</body>
</html>